1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 #include "cgroup_helpers.h"
4
5 #define SOL_CUSTOM 0xdeadbeef
6
getsetsockopt(void)7 static int getsetsockopt(void)
8 {
9 int fd, err;
10 union {
11 char u8[4];
12 __u32 u32;
13 char cc[16]; /* TCP_CA_NAME_MAX */
14 } buf = {};
15 socklen_t optlen;
16 char *big_buf = NULL;
17
18 fd = socket(AF_INET, SOCK_STREAM, 0);
19 if (fd < 0) {
20 log_err("Failed to create socket");
21 return -1;
22 }
23
24 /* IP_TOS - BPF bypass */
25
26 optlen = getpagesize() * 2;
27 big_buf = calloc(1, optlen);
28 if (!big_buf) {
29 log_err("Couldn't allocate two pages");
30 goto err;
31 }
32
33 *(int *)big_buf = 0x08;
34 err = setsockopt(fd, SOL_IP, IP_TOS, big_buf, optlen);
35 if (err) {
36 log_err("Failed to call setsockopt(IP_TOS)");
37 goto err;
38 }
39
40 memset(big_buf, 0, optlen);
41 optlen = 1;
42 err = getsockopt(fd, SOL_IP, IP_TOS, big_buf, &optlen);
43 if (err) {
44 log_err("Failed to call getsockopt(IP_TOS)");
45 goto err;
46 }
47
48 if (*big_buf != 0x08) {
49 log_err("Unexpected getsockopt(IP_TOS) optval 0x%x != 0x08",
50 (int)*big_buf);
51 goto err;
52 }
53
54 /* IP_TTL - EPERM */
55
56 buf.u8[0] = 1;
57 err = setsockopt(fd, SOL_IP, IP_TTL, &buf, 1);
58 if (!err || errno != EPERM) {
59 log_err("Unexpected success from setsockopt(IP_TTL)");
60 goto err;
61 }
62
63 /* SOL_CUSTOM - handled by BPF */
64
65 buf.u8[0] = 0x01;
66 err = setsockopt(fd, SOL_CUSTOM, 0, &buf, 1);
67 if (err) {
68 log_err("Failed to call setsockopt");
69 goto err;
70 }
71
72 buf.u32 = 0x00;
73 optlen = 4;
74 err = getsockopt(fd, SOL_CUSTOM, 0, &buf, &optlen);
75 if (err) {
76 log_err("Failed to call getsockopt");
77 goto err;
78 }
79
80 if (optlen != 1) {
81 log_err("Unexpected optlen %d != 1", optlen);
82 goto err;
83 }
84 if (buf.u8[0] != 0x01) {
85 log_err("Unexpected buf[0] 0x%02x != 0x01", buf.u8[0]);
86 goto err;
87 }
88
89 /* IP_FREEBIND - BPF can't access optval past PAGE_SIZE */
90
91 optlen = getpagesize() * 2;
92 memset(big_buf, 0, optlen);
93
94 err = setsockopt(fd, SOL_IP, IP_FREEBIND, big_buf, optlen);
95 if (err != 0) {
96 log_err("Failed to call setsockopt, ret=%d", err);
97 goto err;
98 }
99
100 err = getsockopt(fd, SOL_IP, IP_FREEBIND, big_buf, &optlen);
101 if (err != 0) {
102 log_err("Failed to call getsockopt, ret=%d", err);
103 goto err;
104 }
105
106 if (optlen != 1 || *(__u8 *)big_buf != 0x55) {
107 log_err("Unexpected IP_FREEBIND getsockopt, optlen=%d, optval=0x%x",
108 optlen, *(__u8 *)big_buf);
109 }
110
111 /* SO_SNDBUF is overwritten */
112
113 buf.u32 = 0x01010101;
114 err = setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &buf, 4);
115 if (err) {
116 log_err("Failed to call setsockopt(SO_SNDBUF)");
117 goto err;
118 }
119
120 buf.u32 = 0x00;
121 optlen = 4;
122 err = getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &buf, &optlen);
123 if (err) {
124 log_err("Failed to call getsockopt(SO_SNDBUF)");
125 goto err;
126 }
127
128 if (buf.u32 != 0x55AA*2) {
129 log_err("Unexpected getsockopt(SO_SNDBUF) 0x%x != 0x55AA*2",
130 buf.u32);
131 goto err;
132 }
133
134 /* TCP_CONGESTION can extend the string */
135
136 strcpy(buf.cc, "nv");
137 err = setsockopt(fd, SOL_TCP, TCP_CONGESTION, &buf, strlen("nv"));
138 if (err) {
139 log_err("Failed to call setsockopt(TCP_CONGESTION)");
140 goto err;
141 }
142
143
144 optlen = sizeof(buf.cc);
145 err = getsockopt(fd, SOL_TCP, TCP_CONGESTION, &buf, &optlen);
146 if (err) {
147 log_err("Failed to call getsockopt(TCP_CONGESTION)");
148 goto err;
149 }
150
151 if (strcmp(buf.cc, "cubic") != 0) {
152 log_err("Unexpected getsockopt(TCP_CONGESTION) %s != %s",
153 buf.cc, "cubic");
154 goto err;
155 }
156
157 free(big_buf);
158 close(fd);
159 return 0;
160 err:
161 free(big_buf);
162 close(fd);
163 return -1;
164 }
165
prog_attach(struct bpf_object * obj,int cgroup_fd,const char * title)166 static int prog_attach(struct bpf_object *obj, int cgroup_fd, const char *title)
167 {
168 enum bpf_attach_type attach_type;
169 enum bpf_prog_type prog_type;
170 struct bpf_program *prog;
171 int err;
172
173 err = libbpf_prog_type_by_name(title, &prog_type, &attach_type);
174 if (err) {
175 log_err("Failed to deduct types for %s BPF program", title);
176 return -1;
177 }
178
179 prog = bpf_object__find_program_by_title(obj, title);
180 if (!prog) {
181 log_err("Failed to find %s BPF program", title);
182 return -1;
183 }
184
185 err = bpf_prog_attach(bpf_program__fd(prog), cgroup_fd,
186 attach_type, 0);
187 if (err) {
188 log_err("Failed to attach %s BPF program", title);
189 return -1;
190 }
191
192 return 0;
193 }
194
run_test(int cgroup_fd)195 static void run_test(int cgroup_fd)
196 {
197 struct bpf_prog_load_attr attr = {
198 .file = "./sockopt_sk.o",
199 };
200 struct bpf_object *obj;
201 int ignored;
202 int err;
203
204 err = bpf_prog_load_xattr(&attr, &obj, &ignored);
205 if (CHECK_FAIL(err))
206 return;
207
208 err = prog_attach(obj, cgroup_fd, "cgroup/getsockopt");
209 if (CHECK_FAIL(err))
210 goto close_bpf_object;
211
212 err = prog_attach(obj, cgroup_fd, "cgroup/setsockopt");
213 if (CHECK_FAIL(err))
214 goto close_bpf_object;
215
216 CHECK_FAIL(getsetsockopt());
217
218 close_bpf_object:
219 bpf_object__close(obj);
220 }
221
test_sockopt_sk(void)222 void test_sockopt_sk(void)
223 {
224 int cgroup_fd;
225
226 cgroup_fd = test__join_cgroup("/sockopt_sk");
227 if (CHECK_FAIL(cgroup_fd < 0))
228 return;
229
230 run_test(cgroup_fd);
231 close(cgroup_fd);
232 }
233